UNIX for Beginners Questions & Answers

what does the below unix command do?

Code:

tail -100f  abcd.log

tail - output the last part of files
f- follow
100???

Moderator's Comments:

Please wrap all code, files, input & output/errors in CODE tags. it makes it far easier to read and preserves multiple spaces for indenting or fixed width data.

Hello houmingc,

Please use cods tags as per forum rules for your commands/Inputs/codes which you are using into your posts. tailcommand is use to get last part of Input_files. So command tail -100 Input_filewill show the last 100 lines of your Input_file.
tail -100f Input_filewill show last 100 lines of your Input_file + it will append the data of Input_file if that grows on standard output. So finally we could say, tail -100 Input_filewill provide you last 100 lines of your Input_file and tail -100f Input_filewill provide you last 100 lines of your Input_file with keeping the cursor on screen to wait for new/appending lines of Input_file, so mostly it is used to monitor the logs(if they are keep on growing/increasing and parallel you are doing some operation whose logs you want to monitor).

Thanks,
R. Singh